Generally, the term “rocket” refers to a cylinder body propelled by a rocket engine which provides thrust to the body by rapid discharge of a jet-stream generated by the burning of a propellant. The jet-stream discharge creates thrust and moves the rocket in a direction opposite to the direction of the jet-stream discharge. One factor which influences rocket dispersion (i.e. deviation of the rocket's thrust line from an intended flight path) during the early stages of flight is the turning moment resulting from jet-stream misalignment. Large dispersion of both guided (such as missiles) and unguided rockets is impermissible for obvious reasons.
Jet-stream misalignment can result from a variety of reasons, including for example inaccurate assembly of the rocket, where the thrust line does not pass through the rocket center of gravity; non-uniform heating of the motor structure before and during burning, which may lead to bending and deviation of the thrust line from the missile's longitudinal (roll) axis; and asymmetric burning, which causes a deviation of jet-stream flow from the nozzle.
One solution for overcoming jet-stream misalignment and the resulting rocket dispersion, which is known in the art, includes causing the rocket to perform multiple quick rotations around the longitudinal axis of the rocket body. Typically around 10 spins of 360° in a second are required. However, this solution provides a limited result as often there may be insufficient time during the burning of the rocket engine for performing the required rotations. Furthermore, it may cause loss of “up position” which may hinder further guiding of missiles.
Thus, there is a need in the art for additional solutions for reducing rocket dispersion caused by jet-stream misalignment.